Lal Kishenchand Advani, leader of the opposition in Lok Sabha and former president of the Bharatiya Janata Party, said that it was unfortunate that the Congress and Left parties treated the allegations against Pratibha Patil, United Progressive Alliance candidate for the presidential election, as a smear campaign by the National Democratic Alliance.

Advani was addressing the national executive of the party in New Delhi on Tuesday.

"The UPA's reaction till date to all the disturbing revelations made about their presidential candidate is that it is "a smear campaign by the NDA. They must understand that whatever adverse has been said about her till now, whether by the widow of the murdered Congress leader, the high court, the Reserve Bank of India [Get Quote] or by TV channels like Aaj Tak antedates her choice as presidential nominee. None of these fora had any interest in maligning her. I, therefore, urge all constituents of the UPA to reconsider their decision," he urged.

The former deputy prime minister said unlike in the past, this time around the presidential election is being keenly watched by the people of India.

Therefore, it is our duty to make them aware of the major issues involved in this election, and the portents of its outcome for the country's future, Advani said.

Sushma Swaraj, who held a press conference on behalf of the party as well as NDA, said that Bhairon Singh Shekhawat had entered the contest despite the stand taken by the Shiv Sena.

"They first boycotted the resolution of the NDA. Then they changed the date of announcement to June 25 and now they have taken a decision, which is based on regionalism. It is an unfortunate decision. Nitin Ghadkari, our state unit president has raised a few questions and given instances when Shiv Sena had not taken a decision based on regionalism. Some members were sent to Rajya Sabha despite the fact that they were not Maharashtrians," she said.